In the fields of manufacturing, inspection, and evaluation of semiconductor devices in which miniaturization is advancing at an accelerated pace, in order to produce devices more efficiently, the inspection and measurement of semiconductor wafers during a manufacturing process has been becoming increasingly important. As the inspection and measurement apparatus of semiconductor wafers during the manufacturing process, various apparatuses employing a charged particle beam are in use. For example, a CD-SEM is used for the measurement of the pattern width of a resist pattern, an electron beam external appearance inspection apparatus is used for defect position detection after wiring formation, and a review SEM is used for defect classification; all these apparatuses are based on scanning electron microscopy technology. Moreover, it is sometimes necessary to observe the defect region that has been detected, by a transmission electron microscope at a high magnification; in such cases, an ion beam processing system is used when cutting out the defect region from the wafer to produce a sample for the transmission electron microscope.
While a wafer is processed with various apparatuses such as for manufacturing, inspection, evaluation and so on to be made into a product as a device, a wafer is placed on a specimen stage, and the specimen stage is moved by a stage transport apparatus in various kinds of wafer processing apparatuses. In the above described charged particle beam inspection and measurement apparatus, it is necessary that the specimen stage with a wafer which is transported from another apparatus placed thereon transports the observation spot of the wafer to a predetermined location it its own apparatus, such as the electron beam irradiation position of the electron microscope. As described so far, while the wafer is processed through several kinds of manufacturing, inspection, and evaluation apparatuses, since a position repeatability in nano-order is required between the respective apparatuses, an origin point adjustment and alignment at a specific point are performed for each apparatus where the processing is performed to create a coordinate system in the current apparatus so that timing to start transporting the wafer, stopping position thereof, and the like are controlled based on the coordinate system.
There are two major factors that affect the transport accuracy of the wafer; one is the mechanical accuracy of the transport apparatus itself, and the other is the expansion of the wafer due to heat. Regarding the former factor, although it has become possible to obtain a braking performance in sub-micron order owing to improvements of the transport apparatus, since it is still difficult to obtain a braking performance in nano order because of the limitation of mechanic control, the above described position repeatability is ensured by acquiring a low magnification image for the confirmation of irradiation position of charged particle beam before acquiring a high magnification image necessary for wafer processing, and to judge the detailed position of the measuring object. It is noted that, in such a case, if the position deviation is so large that the observing object moves out of the field of view of low magnification, the wafer alignment needs to be performed again and thereby the throughput of wafer processing is significantly reduced.
The latter factor of the expansion of the wafer due to heat is a problem that has long been known in the field of semiconductor manufacturing equipment such as ion implantation apparatus, exposure apparatus, and the like. For example, JP Patent Publication (Kokai) No. 9-205080A (1997) (Patent Literature 1) discloses an invention in which a Peltier element is built into a wafer-opposing surface of an electrostatic chuck for holding the wafer, and a thermocouple is disposed above the Peltier element (in the wafer-opposing surface) so that the Peltier element is controlled by the temperature of the wafer sensed by the thermocouple. Further, JP Patent Publication (Kokai) No. 2008-010259A (2008) (Patent Literature 2) discloses a patent of an exposure apparatus in which heating means and a temperature sensor are disposed in an electrostatic chuck, and the above described heating means is heated so as to correct partial distortion of the wafer due to electron beam heating.
The reason why the temperature control technique for the wafer as described above has developed in semiconductor manufacturing equipment is that the requirement for the accuracy of beam irradiation position control is rigorous since redoing is not allowed in the case of manufacturing in contrast to the cases of inspection and measurement. Moreover, in inspection and measurement apparatuses, in order to acquire a high resolution image, in the case of a wafer inspection and measurement apparatus utilizing a charged particle beam, since it is necessary to scan a primary charged particle beam which is focused as narrowly as possible on the specimen, and therefore the beam current cannot be increased very high in terms of the Coulomb effect, the energy of the charged particle beam to be launched into the wafer is small in the wafer inspection and measurement apparatus utilizing a charged particle beam compared with the semiconductor manufacturing equipment, and therefore a position deviation caused by the expansion of the wafer due to heating by charged particle beam has not become a serious problem.